The invention relates to a recycling system of wire saw abrasive grain slurry and centrifugal separators therefore.
Conventionally, a wire saw sakes use of an abrasive grain slurry, in which abrasive grain as a cutting material and a cutting liquid are mixed with each other. Recently, the abrasive grain and the cutting liquid, which have been used, are recovered, separated and recycled for effective use (reduction in cutting cost) of resources or environmental conservation. Documents (1) and (2) intended for recycling of a wire saw abrasive grain slurry are explained below.
The document (1) describes a method and an apparatus for recycling of wire saw abrasive grain slurry, disclosed in Japanese Patent Laid-Open No. 172237/1999.
The document (2) describes a wire saw abrasive grain circulating apparatus, disclosed in Japanese Patent Laid-Open No. 33913/1999, and contents thereof are explained schematically.
The constitution described in the above documents (1) and (2) is problematic in that the fine grain mixed liquid from the first separating means is directly supplied to the second separating means. That is, there are involved problems that separation and recovery of abrasive grain and a cutting liquid are not effected smoothly due to viscosity of the fine grain mixed liquid leading to incapability of efficient separation in the second separating means, and load is liable to apply on a screw of the second separating means and abrasion and damage are liable to generate on the screw, and that amounts of feed of abrasive grain and the cutting liquid cannot be minutely adjusted.
Also, the documents (1) and (2) are problematic in that a specific constitution is not employed for a blade edge of and rotational control of the screw of the separating means. That is, problems are conceivable in association with abrasion, damage or the like on the blade edge or disposition of load.
Further, the documents (1) and (2) are problematic in that a teed rate of an abrasive grain waste liquid, a feed rate of a fine grain mixed liquid, a feed rate of a fresh cutting liquid and feed rates of fresh abrasive grain and a cutting liquid for dilution are not subjected to computer control with the use of not. That is, there are involved problems in incapability of precise adjustment of the respective feed rates, need of or and the like.
Embodiments of the invention will be described below.
An abrasive grain waste liquid used is directed to an undiluted solution tank from a wire saw. The abrasive grain waste liquid in the undiluted solution tank is directed to a first centrifugal separator by way of a first pipe to be separated therein into recycled abrasive grain and a fine abrasive grain mixed liquid for processing. An amount (feed rate) of the abrasive grain waste liquid directed to the first centrifugal separator is input into a hose computer (referred below to as a computer) by way of a net. The input amount of the abrasive grain waste liquid is subjected to arithmetic processing in the computer and settlement in terms of money. In addition, the first centrifugal separator is intended for reduction in wear of a blade edge of a screw by the provision of a cemented carbide chip on the blade edge of the screw, or for achievement of sure feed and serviceability in sure and smooth separated processing. Also, when load is applied on the screw, a servomotor provided with a control unit (feedback, controller, sensor or the like) is used to control the rotating speed of the screw, thus preventing failure of the first centrifugal separator and the screw. If wear and/or failure are caused on the screw of the first centrifugal separator, this is input into the computer with the use of a net as desired. The degree of wear is examined compared with a set dimension, and so the computer performs arithmetic processing of efficiency, endurance time and so on to provide judgment of best and efficient states or the like. This judgment control leads to settlement in terms of Money to be concluded in transaction. Also, repairing of the first centrifugal separator, replacement of parts therefor and the like are subjected to arithmetic processing in the computer to lead to settlement in terms of money to be concluded in transaction.
The recycled abrasive grain separated and processed is directed to a recovered abrasive grain tank through a second pipe. Also, the fine abrasive grain mixed liquid is directed to a separated liquid tank through a third pipe. The separated liquid tank reduces an amount of the recycled abrasive grain being fed to the recovered abrasive grain tank, thereby decreasing mixing, described later, of chips into the recovered abrasive grain tank for ensuring quality of a recovered abrasive grain mixed liquid.
A fine abrasive grain mixed liquid in the separated liquid tank is directed to a second centrifugal separator by means of a fourth pipe, in the course of which a fresh cutting liquid is supplied to the fine abrasive grain mixed liquid by way of a fifth pipe to dilute the same. The purpose of such dilution is to dilute viscosity of the fine abrasive grain mixed liquid to ensure an amount of the fine abrasive grain mixed liquid fed to the second centrifugal separator and to achieve efficient separation into recycled abrasive grain and a recovered cutting liquid in the second centrifugal separator. Also, load on a screw of the second centrifugal separator is reduced and abrasion, damage and the like on the screw are avoided. Further, the purpose of such dilution is to replenish an amount of the recycled abrasive grain fed to the recovered abrasive grain tank. An amount of the fine abrasive grain mixed liquid (feed rate of a fresh abrasive grain mixed liquid) and an amount of a fresh cutting liquid (feed rate of a fresh cutting liquid) are input into the computer by way of the net. Amounts of the fine abrasive grain mixed liquid and the fresh cutting liquid are subjected to arithmetic processing in the computer to lead to settlement in terms of money to be concluded in transaction.
The fine abrasive grain mixed liquid thus diluted is subjected to separated processing into waste abrasive grain and a recovered cutting liquid in the second centrifugal separator, and the recovered cutting liquid is directed to a recovered cutting liquid tank through a seventh pipe.
The recovered cutting liquid tank in the recovered cutting liquid tank is directed to a recovered abrasive grain tank by way of an eighth pipe to be mixed with the recycled abrasive grain in the recovered abrasive grain tank, and fresh abrasive grain for dilution and a cutting liquid, respectively, are added by way of ninth and tenth pipes to create a recycled abrasive grain mixed cutting liquid (recycled abrasive grain cutting liquid). Amounts of a fresh abrasive grain and a fresh cutting liquid (feed rates of a fresh abrasive grain and a fresh cutting liquid) are input into the computer by way of the net. The amounts of the fresh abrasive grain and the fresh cutting liquid are subjected to arithmetic processing in the computer for quality control. Alternatively, the amounts of the fresh abrasive grain and the fresh cutting liquid are subjected to arithmetic processing in the computer to lead to settlement in terms of money to be concluded in transaction.
The recycled abrasive grain mixed cutting liquid is supplied to an abrasive grain supply tank by way of an eleventh pipe, and is supplied to the wire saw by way of a twelfth pipe from the abrasive grain supply tank. Also, an amount of a recycled abrasive grain mixed cutting liquid together with a set amount of a recycled abrasive grain mixed cutting liquid is subjected to arithmetic processing in the computer for quality control. Alternatively, the amount of the recycled abrasive grain mixed cutting liquid is subjected to arithmetic processing in the computer to lead to settlement in terms of money to be concluded in transaction.